1. Field of Invention
The present invention relates to lighting, and particularly to the light of backlights used in displays.
2. Discussion of Background
Electronic displays are used in a wide range of applications. Some electronic displays have a series of spatial light modulators, for example, a backlight (or modulated backlight) and a front modulator.
Elements of the spatial light modulators may be controlled, for example, in response to image data to yield an image that can be observed by viewers. The elements of some spatial light modulators are backlight elements which have multiple states or levels of illumination. The levels of illumination may be, for example, utilized to produce a low resolution version of a desired image which may then be further modulated by an LCD panel to produce a desired image.
Arrays of backlight elements, front modulators, and processing to produce the desired image may be configured, for example, as described in Whitehead et al., U.S. Pat. No. 6,891,672, the contents of which are incorporated herein by reference in their entirety for all purposes. Such arrangements comprise locally dimmed backlit displays, and may also be referred to as dual modulation displays.
In order to operate most efficiently, the backlight elements are calibrated, adjusted, or binned so as to have uniform qualities at a given illumination level. During a post-factory calibration phase, all LEDs in an array may be adjusted so that each LED has the same brightness when driven at the same PWM value. For backlights with RGB LEDs, the LEDs may be further calibrated to have the same hue.